| 479 |
|
} |
| 480 |
|
|
| 481 |
|
/* |
| 482 |
< |
* Possible values for "how" argument in xfer method. Beware that |
| 483 |
< |
* the order of assigned numerical values matters. |
| 482 |
> |
* Possible values for "how" argument in xfer method. |
| 483 |
|
*/ |
| 484 |
< |
private static final int NOW = 0; // for untimed poll, tryTransfer |
| 485 |
< |
private static final int ASYNC = 1; // for offer, put, add |
| 486 |
< |
private static final int SYNC = 2; // for transfer, take |
| 487 |
< |
private static final int TIMEOUT = 3; // for timed poll, tryTransfer |
| 484 |
> |
private static final int NOW = 0; // for untimed poll, tryTransfer |
| 485 |
> |
private static final int ASYNC = 1; // for offer, put, add |
| 486 |
> |
private static final int SYNC = 2; // for transfer, take |
| 487 |
> |
private static final int TIMED = 3; // for timed poll, tryTransfer |
| 488 |
|
|
| 489 |
|
@SuppressWarnings("unchecked") |
| 490 |
|
static <E> E cast(Object item) { |
| 497 |
|
* |
| 498 |
|
* @param e the item or null for take |
| 499 |
|
* @param haveData true if this is a put, else a take |
| 500 |
< |
* @param how NOW, ASYNC, SYNC, or TIMEOUT |
| 501 |
< |
* @param nanos timeout in nanosecs, used only if mode is TIMEOUT |
| 500 |
> |
* @param how NOW, ASYNC, SYNC, or TIMED |
| 501 |
> |
* @param nanos timeout in nanosecs, used only if mode is TIMED |
| 502 |
|
* @return an item if matched, else e |
| 503 |
|
* @throws NullPointerException if haveData mode but e is null |
| 504 |
|
*/ |
| 536 |
|
p = (p != n) ? n : (h = head); // Use head if p offlist |
| 537 |
|
} |
| 538 |
|
|
| 539 |
< |
if (how >= ASYNC) { // No matches available |
| 539 |
> |
if (how != NOW) { // No matches available |
| 540 |
|
if (s == null) |
| 541 |
|
s = new Node(e, haveData); |
| 542 |
|
Node pred = tryAppend(s, haveData); |
| 543 |
|
if (pred == null) |
| 544 |
|
continue retry; // lost race vs opposite mode |
| 545 |
< |
if (how >= SYNC) |
| 546 |
< |
return awaitMatch(s, pred, e, how, nanos); |
| 545 |
> |
if (how != ASYNC) |
| 546 |
> |
return awaitMatch(s, pred, e, (how == TIMED), nanos); |
| 547 |
|
} |
| 548 |
|
return e; // not waiting |
| 549 |
|
} |
| 592 |
|
* predecessor, or null if unknown (the null case does not occur |
| 593 |
|
* in any current calls but may in possible future extensions) |
| 594 |
|
* @param e the comparison value for checking match |
| 595 |
< |
* @param how either SYNC or TIMEOUT |
| 596 |
< |
* @param nanos timeout value |
| 595 |
> |
* @param timed if true, wait only until timeout elapses |
| 596 |
> |
* @param nanos timeout in nanosecs, used only if timed is true |
| 597 |
|
* @return matched item, or e if unmatched on interrupt or timeout |
| 598 |
|
*/ |
| 599 |
< |
private E awaitMatch(Node s, Node pred, E e, int how, long nanos) { |
| 600 |
< |
long lastTime = (how == TIMEOUT) ? System.nanoTime() : 0L; |
| 599 |
> |
private E awaitMatch(Node s, Node pred, E e, boolean timed, long nanos) { |
| 600 |
> |
long lastTime = timed ? System.nanoTime() : 0L; |
| 601 |
|
Thread w = Thread.currentThread(); |
| 602 |
|
int spins = -1; // initialized after first item and cancel checks |
| 603 |
|
ThreadLocalRandom randomYields = null; // bound if needed |
| 609 |
|
s.forgetContents(); // avoid garbage |
| 610 |
|
return this.<E>cast(item); |
| 611 |
|
} |
| 612 |
< |
if ((w.isInterrupted() || (how == TIMEOUT && nanos <= 0)) && |
| 612 |
> |
if ((w.isInterrupted() || (timed && nanos <= 0)) && |
| 613 |
|
s.casItem(e, s)) { // cancel |
| 614 |
|
unsplice(pred, s); |
| 615 |
|
return e; |
| 628 |
|
else if (s.waiter == null) { |
| 629 |
|
s.waiter = w; // request unpark then recheck |
| 630 |
|
} |
| 631 |
< |
else if (how == TIMEOUT) { |
| 631 |
> |
else if (timed) { |
| 632 |
|
long now = System.nanoTime(); |
| 633 |
|
if ((nanos -= now - lastTime) > 0) |
| 634 |
|
LockSupport.parkNanos(this, nanos); |
| 1041 |
|
*/ |
| 1042 |
|
public boolean tryTransfer(E e, long timeout, TimeUnit unit) |
| 1043 |
|
throws InterruptedException { |
| 1044 |
< |
if (xfer(e, true, TIMEOUT, unit.toNanos(timeout)) == null) |
| 1044 |
> |
if (xfer(e, true, TIMED, unit.toNanos(timeout)) == null) |
| 1045 |
|
return true; |
| 1046 |
|
if (!Thread.interrupted()) |
| 1047 |
|
return false; |
| 1057 |
|
} |
| 1058 |
|
|
| 1059 |
|
public E poll(long timeout, TimeUnit unit) throws InterruptedException { |
| 1060 |
< |
E e = xfer(null, false, TIMEOUT, unit.toNanos(timeout)); |
| 1060 |
> |
E e = xfer(null, false, TIMED, unit.toNanos(timeout)); |
| 1061 |
|
if (e != null || !Thread.interrupted()) |
| 1062 |
|
return e; |
| 1063 |
|
throw new InterruptedException(); |
